Operators of certain types of electrical apparatus manipulate a different switch button, key, rotary knob or the like to control each different function of the apparatus. Traditional controls of this kind are convenient to operate and provide fast response to operator input. As such controls are single function devices, identifying labels, settings location symbols, calibration marks and other graphics are permanent markings situated adjacent to or on the controls.
Increasingly, electromechanical controls of the single function kind are being replaced with multiple function controls in which the operator uses a single device to initiate or control a number of different operations. Visual symbols and other graphics that may be needed by the operator in order to utilize the control are presented on a display screen which is situated in the vicinity of the control. The graphics can be changed instantly to enable use of the same control for different purposes. A control of this kind can replace a large number of specialized single function controls and can in fact have virtually unlimited functional flexibility. The keyboard keys, mouse or trackball and video display screen which interface a computer and the user of the computer are an example of multiple function controls of this kind.
Prior multiple function controls of the above described kind have disadvantages that are not experienced by operators of traditional single function controls although this has not been widely recognized. Prior multiple function controls require more complex and prolonged hand movements on the part of the operator and are less comfortable to operate at least for most users.
While the present invention is not limited to use with computers, consideration of the current interfacing of a computer and the operator is illustrative of problems which are inherent in prior multiple function controls.
Much of the operator input to a computer is effected with a mouse or trackball and the computer screen. The following sequence of hand manipulations is required to select a single "pop up" window on a computer screen and then make a selection within that window:
(a) The hand is moved to grasp the mouse or trackball. PA1 (b) Additional hand movement travels the screen cursor to a selected spot on the screen. PA1 (c) Finger movement at the mouse or trackball switch clicks the device to select that specific spot. PA1 (d) Further hand movement travels the cursor to a new spot on the screen within the pop up window. PA1 (e) Further finger movement at the mouse or track-ball makes the selection from the window.
Clearly it would be faster and less taxing to just turn a knob and/or push a switch to make such selections. Complex software, such as four color graphics and picture generation or music sound design and sequencer software, forces the operator to make hundreds or thousands of "clicks and drags" of the mouse or trackball in order to run a single program.
Pushing a switch or turning a knob feels right because it is familiar, it works fast and it satisfies the human mind's natural sensory perceptions. Thus it would be advantageous if multiple function controls gave the operator the immediate response and familiar tactile feel of traditional single function control mechanisms.
Prior efforts to accomplish this have significant limitations. Switch buttons have been positioned adjacent to the perimeters of liquid crystal displays or cathode ray tube screens. The display or screen is then used to create temporary labels which identify the current function of each switch. The visible image areas of the displays or screens are smaller than the total areas of the faces of the devices owing to the presence of thick structural framing, seals and/or bus conductors at the peripheral regions of the devices. Consequently, labels which appear on the screen are located a distance away from the switches which the labels identify. Typically, the label is 5/8 of an inch to 3/4 of an inch away from the switch. This makes it less easy to identify a particular label with a particular switch and increases the possibility of operator error. It is also not possible to situate graphics, such as radial lines or other control setting indicators, at any location around the periphery of a control as is often desirable.
Touch screens, utilizing infrared beams or the like, of the type used as control panels for industrial computer screens or in kiosks in stores, malls, banks or hotels, for example, can also be configured as multiple function controls but also have undesirable characteristics. The response time of touch screens is slow at best. It is often necessary to touch the screen two or three times to enter instructions or data. The feel of a touch screen is not a satisfactory tactile experience for many operators.
The present invention is directed to overcoming one or more of the problems discussed above.